Implementing Hardware Accelerator for Storage Write Cache Management for Identification of Data Age in Storage Write Cache

1. A data storage system comprising: a controller comprising a hardware write cache engine implementing storage adapter write cache management for a data storage write cache comprising: said data storage write cache including a plurality of structures of Cache Lines (CLs), a hash table, and per array of least recently used (LRU) queues; said hardware write cache engine implementing storage write cache hardware acceleration; and said hardware write cache engine performing data age identification including hardware Cache Lines (CLs) manipulation and maintaining hardware counters in said data storage write cache substantially without using firmware; and said hardware write cache engine managing said plurality of structures of Cache Lines (CLs), said hash table, and said per array of least recently used (LRU) queues substantially without using firmware, and providing substantially atomic update of a cache directory and providing substantially atomic updates of said plurality of structures of Cache Lines (CLs), said hash table, and said per array of least recently used (LRU) queues.

2. The data storage system as recited in claim 1 includes said hardware performing data age identification in said data storage write cache on an Array ID or an Array Logical Block Address (LBA) basis.

3. The data storage system as recited in claim 1 wherein said hardware write cache engine performing data age identification includes said hardware write cache engine using an Op Build Number or sequence number within a cache line (CL) for data age identification.

4. The data storage system as recited in claim 3 includes said hardware write cache engine performing hardware manipulation of Cache Lines (CLs).

5. The data storage system as recited in claim 3 includes said hardware write cache engine performing hardware manipulation of Cache Lines (CLs) tracking CL states and said Op Build Number or sequence number within a CL.

6. The data storage system as recited in claim 1 includes providing a cache line (CL) definition including an Op Build Number or sequence number within the CL, said hardware write cache engine incrementing said Op Build Number or sequence number with each cache entry.

7. The data storage system as recited in claim 6 includes said hardware write cache engine incrementing a counter with each cache entry for an Array Logical Block Address (LBA) for tracking said Op Build Number or sequence number.

8. The data storage system as recited in claim 6 includes said hardware write cache engine implementing identification of older versus newer data in said data storage write cache for an array Logical Block Address (LBA) using said Op Build Number or sequence number.

9. A method for implementing storage adapter write cache management in a data storage system comprising: providing a controller comprising a hardware write cache engine managing a data storage write cache; providing said data storage write cache including a plurality of structures of Cache Lines (CLs), a hash table, and per array of least recently used (LRU) queues; providing said hardware write cache engine for implementing storage write cache hardware acceleration; and providing said hardware write cache engine for performing data age identification including hardware Cache Lines (CLs) manipulation and maintaining hardware counters in CLs in said data storage write cache substantially without using firmware; and said hardware write cache engine managing said plurality of structures of Cache Lines (CLs), said hash table, and said per array of least recently used (LRU) queues substantially without using firmware, and providing substantially atomic update of a cache directory and providing substantially atomic updates of said plurality of structures of Cache Lines (CLs), said hash table, and said per array of least recently used (LRU) queues.

10. The method as recited in claim 9 includes providing said hardware write cache engine performing data age identification in storage write cache on an Array ID or an Array Logical Block Address (LBA) basis.

11. The method as recited in claim 9 wherein providing said hardware write cache engine performing data age identification includes said hardware write cache engine using an Op Build Number or sequence number within a cache line (CL).

12. The method as recited in claim 11 includes said hardware write cache engine performing hardware manipulation of Cache Lines (CLs) and updating cache line (CL) states and said Op Build Number or sequence number.

13. The method as recited in claim 11 includes said hardware write cache engine incrementing a counter with each cache entry for an array Logical Block Address (LBA) for tracking said Op Build Number or sequence number.

14. The method as recited in claim 13 includes said hardware write cache engine performing updates to CL states and said Op Build Number or sequence number with each cache entry.

15. The method as recited in claim 11 wherein said hardware write cache engine performing hardware manipulation of Cache Lines (CLs) includes manipulation of an Op Build Number or sequence number within each cache line (CL), and said hardware write cache engine using said Op Build Number or sequence number for data age identification in said data storage write cache for an array Logical Block Address (LBA).